Electric supply system



55cm, 12,, 19330 H. FQALE LQZGAW ELECTRIC SUPPLY SYSTEH E'iled Jam 23,193] .23 Sheets-Sheet l Filed. Jan 23, 193]. 3 Sheeizs-$heet WEI u H.FQALE ELECTRIC SUPPLY SYSTEM $ept m 1933.

Filed Jan. 23, 1931 3 Sheets-Sheet L awful! 1.12.11

y. F Efr i Patented Sept. 12, 1933 UNITED STATES PATENT ELECTRIC SUIPLYSYSTEM Application January 23, 1931, Serial No. 514L825 and in GreatBritain March Il, 1930 13 @laims.

This invention relates to electrical installations, particularly trainlighting installations in which the conditions make it difficult to meetrequirements satisfactorily. One object is the attainment of a closerlamp voltage regulation, and another the provision of a regulator andassociated gear which is simple to manufacture, is of robust andreliable character, is little sensitive to temperature influences, andrequires little supervision. A further object is to ensure that thebattery is always charged at a rate suitable to its state, whether ornot the lamps are in circuit.

Qne example of the invention as applied to train-lighting will now bedescribed: In the accompanying drawings Fig. 1 is a circuit diagram.Fig. 2 an elevation of the apparatus. Fig. 3 a plan thereof and Fig. 4 across section on the line 4-4 of Fig. 2.

Referring first to Fig. 1 the installation coinprises the followingcomponents: A shunt wound dynamo a, a battery h, load circuits 0, elsetin-magnetic switch means (1 controlling the cutting in and out of thedynamo a and of the socalled lamp resistance, an electro-magneticregulator e, electro-magnetic control means f operative upon saidregulator e, an output control switch g, and a pilot switch it foractuating an electro-magnetic lighting switch 7'.

The switch means it comprises a contact 3 controlled by a solenoid 4 andthree contacts 5, 6, 7 controlled by a solenoid with three windings 8,9, 10. The cut-in contact 6 is in series with a series winding 8 in thepositive lead from the dynamo.

A series winding 9 is in the positive lead of the battery b. A potentialwinding 10 is connected across the dynamo a. The contacts 7 and 3 areshort-circuiting contacts across two sections ll, 12 of lamp resistance.

The regulator e comprises a contact 13, the pur-= pose of which will bereferred to, regulator contacts 14 connected to tappings in dynamo fieldresistance 15, a stabilizing resistance 15 and a solenoid comprisingmain windings l7, l8 and 19. The winding 17is a potential windingconnected between a negative lead and, through a sec== .tionalresistance 21, the positive lead from the dynamo. 18 is a series windingshunted by the stabilizing resistance 16 and connected between thebattery b and the winding 9. 19 is a winding 0 located in the circuit ofthe dynamo field winding between it and the resistance 15.

The automatic control means 1 comprises the resistance 21 tapped at 210.and 21b, a contact device 22, 22a, 22b and a contact device 23,solenoids 24, respectively controlling said contact devices,

and calibrating resistances 32,33. The tapping 21a is connected to thefixed contact 22c and to one fixed contact of the device 23. The tapping21b is connected to the other fixed contact of the device 23. Thesolenoid 24 is connected between the positive side of the load circuits0, to which the movable contact 22 is also connected, and the contact 5.The fixed contact associated with said contact 5, which is shunted by aresistance 5 is connected in turn to the negative main through theresistance 32. The solenoid 25 is connected between the fixed contact22?), and, through the resistance 83, the negative main. Said contact2219 is also connected to the winding l -which is itself connected,through the contact device 13 and an auxiliary winding on the regulator,to the negative lead 20.

The output control switch g comprises a sole hold 36, a contact device3611 and a calibrating shunt resistance 3673. main positive lead fromthe dynamo as is an auxiliary winding 37 on the regulator 6 when thecontact device 36a is open. Closure of said contact device 36a shortcircuits the winding 37.

The switch it has a manually operated arm 26 connected to the batterypositive whereby either the on winding 27 or the off winding 28 of theelectro-magnetic lighting switch 7' can he energize to open or close thecontact 29 in the positive lamp lea Assuming a concrete example of a 25volt battery h, the operation of the installation is as follows:-

When the dynamo has reached a speed suf ficient to generate 28 to 27volts, the shunt coil iii Y is sunlciently energized to close the cut-incontact 6 and auxiliary contact 5. Current then flows through the seriescoil 8, the contact 6 and the series coil 9. This strengthens the actionof the cut-in solenoid so that, it opens the contact '7 which so far hasbeen closed. If the battery 22 is being charged with the lamps off, thecurrent then passes through the series coil 18 of the regulator and thebattery b to the negative terminal of the dynamo. Current also flowsthrough the whole of the resistance 21 and the regulator potential coil17. It is mainly due to the action of this coil 17 that the regulatorfunctions according to requirements, the dynamo voltage beingautomatically adjusted so that it remains a little alcove the batteryvoltage.

On commencing to charge a completely discharged battery with the lampsoff, a large current flows through the series coil 18 this series coil18 being wound so that it assists the shunt The solenoid 36 is in theHill coil l'ltokeepthechargetothebatterywithin permisible limits. Thefunction of the stabilizing resistance 18 is to take a fraction of themain battery current; by properly proportioning said resistance, theseries coil 18 can be calibrated for acertainmaximumcurrenttobeallowedtopass to the battery. With the rise of battery voltage, say to about 32volts, the current in the series .coil 18 is reduced owing to thebattery being nearly charged, whereas that in the shunt coil 1'! isincreased, so that finally the shunt coil takes complete control of theregulation, reducing the charging current to a negligble amount. It isdesirable that batteries should always be recharged as soon as possible;when freshly rim down they can berecharged with this mode ofregulation'so that they receive 30% of their total charge during thefirst hour. The charging current may be gradually reduced to about 10%of the maximum at the end of five hours.

The coil 19 is wound to opposse the potential coil 1'7 and the seriescoil 18. Below the cut-in voltage, the effects of 17 and 19 are nearlybalanced so that the regulator does not tend to move, but as soon as thecontact 6 is closed the coil 18 assists the coil 17. The contacts 14 arethen opened one at a time as the dynamo speed increases, the contact 13closing at about the time contact 14a is opened. As the contacts 14open, more of the resistance 15 is inserted in the circuit of the dynamofield 1 and the coil 19 so as just to keep the dynamo voltage a littlehigher than the battery voltage and to maintain the charge as required.The coil 19 gradually be The reverse takes place when the speed isreduced until all the contacts 14 are closed and the contact 6 cuts outthe dynamo.

Assume that the lamps c are now switched on and further that the contact6 is closed and that '7 is opened. The dynamo current divides at 34,

part going to the battery as previously described and the remainderflowing through the lamp resistance 11 and the contact 3 to the lampload c. Owing to the voltage drop in the lamp resistance 11, the lampvoltage is about 3 volts less than the battery voltage. Thisdeflerence'is necessary so that the battery can be charged withoutoverloading the lamps. This continues until, due to the gradual rise ofthe battery voltage, the lamp voltage reaches 25 to 26 volts whereat thefollowing operations happen in this order:

Current passing from the positive lamp lead through the coil 24, theswitch 5 and the resistance 32 sumciently excites this coil 24 for thecontact 22 to be closed upon the contacts 22a and 221). Three branchcircuits are established.

Firstly there is a circuit through contact 2241 to the tapping 21a inthe resistance 21, thence throughthe shunt coil 17 to the negative pole.This strengthens the coil 17 as a part of the resistance 21 is shortcircuited; the regulator therefore automatically inserts more resistance15 into the circuit of thedynamo field coil 1 and slightly reduces theoutput.

Secondly a circuit is made from contact 22b through the coil 4 andthence through the contact 13 and coil 35 to the negative lead 20. Theresultant opening of the contact 3 causes further lamp resistance 12 tobe inserted in the lamp circuit. This causes a further drop of 3 voltsin the lamp voltage so that the lamps burn at about 6 volts less thanthe battery voltage. This insures thatthebatterywillbefullychargedevenwhen all the lamps are in use.

Thirdly over the contact 221) a circuit is made throughthecoil25and33tothenegative main. Owing to its self induction this coil 25 is not, at26 volts, excited sumciently rapidlytoclosecontact23beforethecontact3opensand the voltage drop'referred tooccurs, but when the voltageofthelampsrisesagainto26volts ora valueslightly thereabove, said coil 25 becomes strong enough to close thecontact 23, current then passing from 22a-to 23 andthence via 21b andthe shunt coil 17 to the negative lead. This still further strengthensthe action of the coil 17, as nearly all the resistance 21 is now shortcircuited; more field resistance 15 is inserted due to more contacts 14being opened. This reduces the dynamo charges to the battery, whichshould be nearly charged.

Naturally there is no tendency for current to flow through the coil 24before the lamp switch contact 29 is closed so that the control device Iis never operative except when the lamps are on.

Ifthetrain slows down, the regulator gradually closes the contacts 14 inorder from the left; (Figure 1) on contact 140 being reached the contact13 is opened. This de-energiaes the coil 4 andcloses the contact 3 whichcuts out lamp resistance 12. With further slowing down the contacts 5and 6 are opened and 7 is closed. This cuts out lamp resistance 11, andthe load is supplied by the battery. The opening of the contact 6 at theproper moment is accelerated by the reversal of the current in theseries coil 9 due to the battery taking over the lamp load from thedynamo. This prevents reverse current passing to the dynamo andensuresan earlier cut-out when lamps are in circuit.

If a small lamp load should be switched on when the battery is wellcharged and the dynamo is running at average speed, the regulator mayregulate at a lower voltage than the battery volts, which may be as highas 2'7 at the moment. There will he a discharge from the battery to thelamps for a few minutes, the dynamo being cut out by the opening of thecontact 6; when the peak of the battery voltage has discharged down toabout 25 volts, the contact 6 will close and the regulator willre-adjust itself and the dynamo take up the load again. Although thecontact 5 will open with the contact 6, sufiicient current will passthrough the resistance 5' to the solenoid 24 to keep the contact 22closed until the contact 5 again closes. Also when cut-out occurs as thedynamo slows down the solenoid 24 will remain sumciently excited, due tothe current passing through the rwistanoe 5', to keep the contact 22closed until the lamp voltage falls to'24. This, with full lamp load,takes place almost simultaneously with the cut-out, but, with a smalllamp load and the battery well charged, a few minutes may elapse beforethe contact 22 is opened.

When the dynamo is cut out, the lamp current passes from the batterypositive through the series coil 18 to the series coil 9, then throughthe closed contacts '1 and 3 and the contacts 29 of the lighting switchto the lamps. When the dynamo is running at normalspeedand the lamps aresaid contact 13.

gizes the coil and ensures complete opening of.

It may be desirable to couple lighting, battery and other mains throughfrom coach to coach 01 a train. In these circumstances the failure of anumber of dynamos on the train, increasing the load on the remainingdynamos, might cause the fuses oi the latter to blow unless their outputis under control. In the present arrangement this control is provided bythe coil 37 on the regulator. This coil is normally short circuited bythe contact 36a but when the output current through the coil 36 reachesa predetermined amperage the coil 36 opens the contact 36a whereby thecoil 37 becomes operative to assist the shunt coil 17 inlimiting thedynamo output.

Referring now more particularly to,l?'igs. 2-4

the cores oi the several solenoids are constituted as pistons. Theplunger core 40 of the regulator (Fig. 4) works in a brass tube 4.1which is soldered to a core part 42 screw threaded for connection in anadjustable manner to a supporting frame 4'7; this ensures air tightnessexcept for leakage past the piston 40, thereby establishing a dash potaction, while also ensuring that the tube shall be eflectually heldagainst accidental movement without having to be clamped and possiblyinjured by mechanical means. i

The seven solenoids 4, (8-9-10), (17-18- l9-35-37) 24, 25, 27, 28 andthe associated components are all mounted on the single robust frame 47which is carried by teet 48 within a water and dust tight casing oi!which the base 49 is alone shown. In this way the parts are largelyrelieved of twisting strain. The contact 13 is a spring blade having anatural bias towards an adjusting contact screw as and is moved awayfrom the screw by a tapered bar 51 which is operated (Fig. 4) by thesolenoid piston 40 and serially disengages the contacts 14, in orderfrom the left, from a common short-circuiting contact 52. The variationof the resistance of the path over a contact 14 with the variation ofmechanical pressure as the contact 14 is moved away from the contact 52makes the resistance variation effected by the regulator a gradual one.The contact 52 is a length of carbon attached by screws 52a to a carrier52b of angle section mounted to slide on a support 52c oi. similarsection and held against separation therefrom by screws 52d, Fig. 3, theheads of which take into slots 52s in the support 520.

A link 53 pivoted to a lug on the carrier 52?) couples the contact 52 toan arm 54 pivoted at 54a and encircled by a spring 55 against the actionof which it can be moved towards the right by a lever 56 loosely engagedby the piston o! the lights ofi" switch solenoid 2'7. Thus the contact52 is r'eciprocated every time the lights of! solenoid is energized andlie-energised,

an emergencypush tor. tripping the piston of the solenoid 27 when it maybe desired to open the switch 29 manually.

As most of the wear due to the action of the current takes place on thepositive contact, the long main carbon contact 52 is'made positive tothe smallliiting contacts 14, as it is more easily replaced and can beturned to present new working races, being rectangular in section. Allthe working faces of the regulator contacts are in the vertical plane toallow dust to fall freely away.

I claim:-

1. An electrical installation such as a train lighting installation,comprising in combination with a dynamo connected to a battery and to ano load circuit through a load switch, a field circuit for the dynamo, avariable resistance in said field circuit, an electro-magnetic regulatoroperative to vary said resistance and having its principal windingconnected in shunt across the is; dynamo, resistance in circuit withsaid winding for limiting its excitation while the load switch is openand the battery alone is receiving current from the dynamo or, the loadswitch being closed, while the load voltage is below a predetermined iiivalue, and automatic relay means connected to said load circuit andhaving contacts connected to the last named resistance, said relay meansbeing operative in succession for reducing said resistance on the loadvoltage attaining said value lid and for further reducing the same onsaid voltage subsequently attaining substantially the same value. v

2. An electrical installation comprising in combination with a dynamoconnected to a battery audio 9. load circuit through a load switch, afield circuit for the dynamo, a resistance in said field circuit, anelectro-magnetic regulator operative to vary said resistance andcomprising a predominating shunt winding across the dynamo 12.5 and aseries winding in circuit with the battery, resistance in series withsaid shunt winding for limiting its excitation while the load switch isopen and the battery alone is receiving current from the dynamo or, whenthe load switch is 1.53 closed, while the load voltage is below apredetermined value and automatic relay means connected to said loadcircuit and having contacts connected to the last named resistance, saidrelay means being operative in succession for reducing said resistanceon the load voltage attaining said value and for further reducing thesame on said voltage subsequently attaining substantially the samevalue.

3. An electrical installation comprising in combination with a dynamoconnected to a battery and load, a field circuit for the dynamo, aresistunce in said circuit, an electro-magnetic regulater operative tovary said resistance and compriaing a predominating shunt winding across11 the dynamo and a series winding connected in the hold circuit,resistance in series with said shunt winding for limiting its excitationwhile the battery alone is receiving current from the dynamo or the loadvoltage is below a predetermined value, and automatic relay meansconnected to said load circuit and having contacts connected to the lastnamed resistance, said relay means being operative in succession forreducing said resistance on the load voltage attaining said value andfor further reducing the same on said voltage subsequently attainingsubstantially the same value.

4. An electrical installation comprising in combination with a dynamoconnected to a battery and a load circuit, a field circuit for thedynamo, a resistance in said circuit,an electro-magnetic regulatoroperative to vary said resistance and comprising a predominating shuntwinding across the dynamo, a series winding connected in the fieldcircuit and a series winding in circuit with the battery, resistance inseries with said shunt winding for limiting its excitation while thebattery alone is receiving current from the dynamo or the load voltageis below a predetermined value and automatic relay means connected tosaid load circuit and having contacts connected to the last namedresistance, said relay means being operative in succession for reducingsaid resistance on the load voltage attaining saidvalue and for furtherreducing the same on said voltage subsequently attaining substantiallythe same value.

5. An electrical installation comprising a dynamo connected to a batteryand a load circuit, a field circuit for the dynamo, resistance in saidfield circuit, a regulator comprising a principal shunt winding acrossthe dynamo, an auxiliary shunt winding connected across the loadcircuit, contact means operative to vary said resistance and a contactarranged in series with said auxiliary shunt winding and operativelyconnected with the regulator in such manner as to be closed at apredetermined stage of the action of the regulator, such closurecompleting the shunt circuit of the auxiliary winding, imparting aforward impulse in the action of the regulator and insuring definiteclosure oi said contact, resistance in series with the shunt winding forlimiting it excitation, and electro-magnetic relay means connected tosaid load circuit and adapted for re- .ducing the last named resistanceon the load voltage attaining a predetermined value and for -furtherreducing the same on said voltage subsequently attaining substantiallythe same value.

6. An electrical instaliationasclaimedinclaim 4, comprising in additionan auxiliary shunt regulator winding connected across the load circuit,and an auxiliary contact device, in series with said winding, andoperatively connected with the regulator in such manner at apredetermined stage of the action of the regulator, said windinginsuring clearly defined operation of saldcontact substantially asdescribed.

7. An electrical installation comprising a dynamo, main leads connectingthe dynamo to a battery and a load circuit, a field circuit for thedynamo, resistance in said field circuit; a regulator comprising a shuntwinding across the dynamo, and contact means operative to vary saidresistance; resistance in series with the shunt winding for limiting itsexcitati n. electromagnetic control means connected to said load circuitand adapted for reducing the last named resistance on the load voltageattaining a predetermined value and for further reducing the same onsaid voltage uently attaining a predetermined value, and an emergencyoutputlimiting means comprising a series winding on the regulatorconnected in series with one of said main leads, and an automaticshort-circuiting device normally maintaining a short circuit across saidseries winding and constructed to open and divert the current throughsaid winding upon the attainment of a predetermined output.

8. An electrical installation as claimed in claim 4, comprising inaddition an emergency outputlimiting regulator-winding in series withone o! the main leads connecting the dynamo to the battery and loadcircuit and an automatic shortcircuiting device normally maintaining ashort circuit across said output-limiting winding and constructed toopen and divert the current through said winding up n the attainment ofa predetermined output.

9. Electrical regulating means for an installation embodying a dynamohaving a field circuit and connected to a battery and a load circuit,-

comprising a sectional resistance in the field circuit, a shunt solenoidwinding across the dynamo, an armature influenced by said winding, shcrtcircuiting contacts consisting of a carbon bar and movable membersconnected across sections 01' said resistance, actuating meansoperatively connected with said armature and engaging said movablemembers for opening and closing said contacts in succession, eachcontact being opened or closed slowly so that the resistance in circuitI is modified gradually, resistance in series with said shunt windingfor limiting its excitation, and electro-magnetic relays connected tosaid load circuit and having contacts connected to the last namedresistance, said relays being operative in succession for reducing saidon the load voltage attaining a predetermined value and for furtherreducing the same on said voltage subsequently attaining substantiallythe same value.

10. Electrical regulating means as claimed in claim 9, in combinationwith an automatic switch actuatedperiodicallyintheoperationortheimstallation, for importing a penodical slldingmctiontothecarbonbar-contacttoheep I thesameclean,andanoperativeconnectionbe-'mtween said and the automatic switch.

11. An electrical installation comprising incombinationwithadynamoconnectedtoafield circuitand. through a cut-inswitch, to a battery,andaload,ainssidclrwit. an electro-msgneticregulator operative to vary said resistance and having its principalwinding connected in shunt across the dynamo, resistanceincimuitwithsaidwindingi'orlimitingitsexcitation while the battery aloneis receiving current from the dynamo or the load voltage is bdow apredetermined value, automatic control means connected to said loadcircuit and adapted ior reducingthelastnamedresistanceontheload voltageattaining said value and for further re- 136 ducing the same on the loadvoltage subsequently attaining a predetermined value, a in two parts inseries with the load-an auxiliary contact on the cut-in switch operativefor cuttingonepartotsaidresistanceinandoutoi'lw circuit, and anelectro-magnetic device connected 7 to said load circuit and operativeior cutting theother partoi'saidresistanceinandoutot circuit at apredetermined stage of the raulaticn.

12. An electrical installation as claimed in claim 5, comprising inaddition resistance in two iecccee tact device, to cut in one part ofsaid resistance in series with the load.

13. An electrical installatien comprising in combination with a dynamoconnected to 8b bet tery and a load through a cut-in switch, & fieldcircuit for said dynamo, a resistance in said circuit, anelectro-magnetic regulator operative tc vary said resistance and havingits principal winding connected in shunt across the dynamo, resistancein circuit with said winding for limiting its excitation while thebattery alone is receiving current from the dynamic or the iced voltageis below a predetermined value, successively excited electro-megxieticrelay means excitation circuits of which are connected to iced circuits,e subsidiery contact

